1. Name the following compounds:
Monday, November 17, 2014
Objective: Students will be able to draw electron dot diagrams for covalent molecules.
Warm-Up:
Name the following compounds:
S4N2
Na2O
Cr(MnO4)3
Agenda:
Electron Dot Diagram Notes and Practice

2. Electron Dot Diagrams

3. Review
Electron Dot Diagrams are a short hand way to show the valence electrons in an atom.
Valence electrons: are the number of electrons in the outermost energy level of the atom.

4. Review A covalent bond is between two or more non-metals.
When atoms don’t have 8 valence electrons, they can share electrons between them in order to get 8.
We can also draw Electron Dot diagrams to show how the electrons are shared in a molecule.

5. Types of Covalent Bonds
Single Bond: two atoms sharing 2 electrons
Double Bond: two atoms sharing 4 electrons
Triple Bond: two atoms sharing 6 electrons

6. Brain Break: Count-Up

7. Steps to Draw Electron Dot Diagrams:
Determine the arrangement of atoms and draw a skeleton structure.
The central atom is usually the one with the lowest electronegativity or the single atom.
The central atom is NEVER hydrogen!
Draw the Electron Dot Diagram for each atom.
Remember: you can find the valence electrons by the Group the element is located in.

8. Steps (cont.): Connect the atoms with a single line.
This line denotes the 2 electrons being shared.
Check to see if all atoms have the desired amount of valence electrons.
Remember: Hydrogen and Helium only want two electrons to be happy and Boron is unique because it only wants 6 electrons to be happy. All other elements want 8.

9. Examples:
CH4
H2O2
BF3

10. What happens if there aren’t enough lone pairs for all to have 8?
Add an “extra” bond for every 2 electrons you’re short!
CO2 N2